What is Lean Manufacturing?

An introduction to essential Lean Manufacturing principles, tools, and our best examples.

There is nothing so useless as doing efficiently that which should not be done at all.

~Peter F. Drucker

Lean manufacturing or lean production, often simply "lean", is a systematic method for the elimination of waste ("Muda") within a manufacturing system. Lean also takes into account waste created through overburden ("Muri") and waste created through unevenness in work loads ("Mura").

Lean Manufacturing Key Tools & Principles

Lean Manufacturing relies on a number of key tenents, tools and principles following the Japanese method of 'Kaizen' (or 'change for the better'). Below are a few of the most critical Lean Manufacturing tools, employed to transform companies & manufacturers into Operational Excellence practitioners.

Takt Time

In the world of Lean Manufacturing, takt time is the rate at which the finished product needs to be completed, in order to meet the customer demand. Outside of Lean, the term references the german word for a Baton used to keep a tempo, or a 'heartbeat'.

The Takt Formula

Takt = T/D

Where T is Time available to create the product/service.

D is a demand for the number of units

T gives information on production pace or units per hours.

Example

An example of Takt Time would be as follows:

A company has a demand for 400 units a day, and operates for 800 minutes = 800 minutes / 400 units = a Takt Time of 2 minutes per unit.

5S

The 5S methodology is a helpful Lean Manufacturing tool as it offers the straightforward 5-step process to ensuring the work area is organized and running efficiently - i.e. there is no wasted time whilst workers search for items/papers. The 5 s's are:

Sort (eliminate that which is not needed)

Set In Order (organizing the remaining items)

Shine (cleaning and inspecting the work area)

Standardize (writing out and confirming expected standards for the above)

One-Piece / Continuous Flow

The antithesis to 'batch' production, continuous flow manufacturing is the process of keeping a product moving from the beginning of production to the completion of the product. It is used in manufacturing to maximise efficiency against 'batching', as the next product can be introduced to the process as soon as the one before has completed step one.

'Going to Gemba'

Gemba(現場, also spelt less commonly as genba) is a japanese term meaning "the real place." Japanese police could refer to a crime scene as gemba, and TV reporters often refer to themselves as reporting live from gemba.

Lean Manufacturing, Gemba is a philosophy that expresses the principle of going to the shop floor. It reminds leadership within a company practising Lean to visit the plant floor, and gain understanding of the 'real action'. Going to Gemba provides leadership with an understanding of the real processes and day-to-day undertaking of Lean principles.

Lean Manufacturing: Steps for a Successful Gemba Walk

Take a look at Mike Serena's best advice for a positive Gemba walk - read the full article here.

Create a premise or hypothesis that explains why you believe the topic needs to be addressed. An area leader might pose questions like: a) “I believe that we have excess WIP in and around our production areas causing excess lead time in delivering products to our customers. Let’s go take a look.”, or b) “I have a hunch that our absenteeism and excessive operator rotation could be contributing to our increase in production defects, or c) Let’s go and see what we can find out.”, or d) “I suspect that our metric boards are not identifying the root causes of issues. Let’s take an hour and review the effectiveness of our metric board countermeasures and assignments.”

Formalize a list of questions to review during the gemba session. For example, here are some questions that you might ask when focusing on equipment and tool maintenance: a) Is there evidence of a formal preventative maintenance and auditing program?, b) Is a timetable and tracking sheet posted near critical tools and equipment?, or c) Are operators involved in daily equipment and tool maintenance? or d) Have we conducted a Pareto analysis of our unscheduled equipment downtime?

Share your experiences and feedback as you walk through the area or process. Be sure to keep the comments and examples reinforcing and constructive.

Make appropriate notes and assign follow up homework. Use a “what, who and when” format to track assignments and create accountability.

Establish how often you will conduct gemba sessions with your team. Frequency should be based on desired skill development as well as issue severity.